(1) Field of the Invention
The present invention relates to a piloting assistance system and to an aircraft including said system.
More particularly, the piloting assistance system lies in the technical field of helmet-mounted devices for displaying information, sometimes referred to as a “helmet display or visor”.
It should be observed that the term “piloting assistance system” is used to cover both a system for assisting short-time piloting as such, and also a system for providing assistance in navigating and monitoring the aircraft.
(2) Description of Related Art
Devices are known that present an aircraft pilot with an image representing the environment outside the aircraft, on the basis of night vision or infrared sensors, or when weather conditions are bad, for example. The image is displayed for example on the pilot's helmet-mounted display means, or indeed on so-called “head-up” display means.
It is recalled that when the pilot looks at the outside environment through the windshield of an aircraft, it is common practice to say that the pilot is in a “head-up” position. Conversely, when the pilot is looking at the inside of the cockpit, and in particular at an instrument panel, it is common practice to say that the pilot is in a “head-down” position.
By way of example, the device known under the name “VIGILX®” is known.
That device includes infrared optical cameras for taking a panoramic night image or for use when flying with reduced visibility, in particular.
Furthermore, it is possible to display a digital representation of the environment superimposed on the image as obtained from that device, the digital representation being taken from a digital model of the terrain.
The image may be displayed on a “head-down” screen or indeed it may be projected onto a visor of a helmet.
A device is also known that has a piloting camera with the camera's line of sight being slaved to the position of a pilot's helmet. However, it will be understood that the device is then controlled solely by the movements of the head of only one member of the crew.
It is also common practice to perform a cyclic redundancy check (CRC) for detecting the presence of errors in a signal. Reference may be made to the literature to obtain more information about such a check.
It is also possible to perform such checking, e.g. in order to verify that the image sent to a “head-down” screen or indeed to a helmet visor is not erroneous.
Nevertheless, it should be observed that the calculation needed is relatively complex and lengthy to perform.
Furthermore, the technological background includes in particular the following documents: EP 1 116 210 B1; EP 1 344 021 B1; EP 1 757 906 A2; WO 2005/124685 A1; EP 2 254 039 A1; and EP 1 762 825 A2.
Document EP 1 116 210 B1 describes a flat screen system for displaying data relating to aircraft system parameters, the system having a flat screen and two processors, each interfaced with a graphics color generator.
Document EP 1 344 021 B1 relates to a flat screen display system.
Similarly, document EP 1 757 906 A2 relates to such a system that is provided with a general purpose processor receiving data from on-board sensors and with a graphics processor for generating pixelized images from a video memory, the general purpose processor including an integrity-checking function for verifying at least one pixel of the image.
Document WO 2005/124685 A1 describes a system for verifying the accuracy of an image generated by a display processor, by using a correlator circuit.
Document EP 2 254 039 A1 describes a display module having means for verifying a portion of an image generated by a processor.
Document EP 1 762 825 A2 relates to a flat screen provided with means for verifying the integrity of an image.
Document US 2010/0123839 describes a method serving in particular to produce three-dimensional images.
In that method, an image is produced and information relating to the position of the head of a person is determined. Under such circumstances, the computer determines which light-emitting diodes (LEDs) of a display means should be used for emitting images respectively and sequentially to the left eye and to the right eye.